number of Global Positioning System (GPS) devices has grown rapidly in recent years among military, civil and commercial users around the world. In general, GPS is a space-based satellite navigation system that provides location and time information. GPS may function anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. Thus, GPS may not be accessible inside buildings, subterranean locations, or underwater. GPS has a variety of applications on land, at sea, and in the air. For example, GPS may facilitate activities such as banking, mobile phone operations, navigation of commercial aircraft and boats, scientific studies, tracking, and surveillance.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.